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/*TU*
    
    TombUPnP - a library for developing UPnP applications.
    
    Copyright (C) 2006-2010 Sergey 'Jin' Bostandzhyan <jin@mediatomb.cc>
    
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License version 2.1 as published by the Free Software Foundation.
    
    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.
    
    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
    
    $Id: ThreadPool.h 2081 2010-03-23 20:18:00Z lww $
*/
#ifndef THREADPOOL_H
#define THREADPOOL_H

#ifdef __cplusplus
extern "C" {
#endif

//Size of job free list
#define JOBFREELISTSIZE 100

#define INFINITE_THREADS -1

#define EMAXTHREADS (-8 & 1<<29)

//Invalid Policy
#define INVALID_POLICY (-9 & 1<<29)

//Invalid JOB Id
#define INVALID_JOB_ID (-2 & 1<<29)

typedef enum duration {SHORT_TERM,PERSISTENT} Duration;

typedef enum priority {LOW_PRIORITY,
		       MED_PRIORITY,
		       HIGH_PRIORITY} ThreadPriority;

#define DEFAULT_PRIORITY MED_PRIORITY //default priority used by TPJobInit
#define DEFAULT_MIN_THREADS 1	      //default minimum used by TPAttrInit
#define DEFAULT_MAX_THREADS 10	      //default max used by TPAttrInit	
#define DEFAULT_JOBS_PER_THREAD 10    //default jobs per thread used by TPAttrInit
#define DEFAULT_STARVATION_TIME	500   //default starvation time used by TPAttrInit
#define DEFAULT_IDLE_TIME 10 * 1000   //default idle time used by TPAttrInit
#define DEFAULT_FREE_ROUTINE NULL     //default free routine used TPJobInit
#define DEFAULT_MAX_JOBS_TOTAL 100    //default max jobs used TPAttrInit

#define STATS 1 //always include stats because code change is minimal


//Statistics
#ifdef WIN32 // todo: check why STATSONLY fails during compilation
 #undef STATS
#endif

#ifdef STATS
 #define STATSONLY(x) x
#else
 #define STATSONLY(x)
#endif

#ifdef _DEBUG
 #define DEBUG 1
#endif

//DEBUGGING
#ifndef WIN32
 #ifdef DEBUG
  #define DBGONLY(x) x
 #else
  #define DBGONLY(x)
 #endif
#endif

#include "LinkedList.h"
#include <sys/time.h>
#include "FreeList.h"

#include "ithread.h"
#include <errno.h>
#define EXPORT 
typedef int PolicyType;
#define DEFAULT_POLICY SCHED_OTHER
#define DEFAULT_SCHED_PARAM 0 //default priority

/****************************************************************************
 * Name: free_routine
 *
 *  Description:
 *     Function for freeing a thread argument
 *****************************************************************************/
typedef void (*free_routine)(void *arg);
typedef void (*free_thread_func)(void);

/****************************************************************************
 * Name: ThreadPoolAttr
 *
 *  Description:
 *     Attributes for thread pool. Used to set and change parameters of
 *     thread pool
 *****************************************************************************/
typedef struct THREADPOOLATTR
{
  int minThreads;     // minThreads, ThreadPool will always maintain at least
                      // this many threads

  int maxThreads;     // maxThreads, ThreadPool will never have more than this
                      // number of threads

  int maxIdleTime;    // maxIdleTime (in milliseconds)
                      // this is the maximum time a thread will remain idle
                      // before dying

  int jobsPerThread;  // jobs per thread to maintain

  int maxJobsTotal;   // maximum number of jobs that can be queued totally.

  int starvationTime; // the time a low priority or med priority
	              // job waits before getting bumped
                      // up a priority (in milliseconds)

  PolicyType schedPolicy; // scheduling policy to use

} ThreadPoolAttr;

/****************************************************************************
 * Name: ThreadPool
 *
 *  Description:
 *     Internal ThreadPool Job
 *****************************************************************************/
typedef struct THREADPOOLJOB
{
  start_routine func; //function
  void *arg;          //arg
  free_routine free_func; //free function
  struct timeval requestTime; //time of request
  int priority;       //priority of request
  int jobId;         //id 
} ThreadPoolJob;

/****************************************************************************
 * Name: ThreadPoolStats
 *
 *  Description:
 *     Structure to hold statistics
 *****************************************************************************/

STATSONLY(

typedef struct TPOOLSTATS
{
  double totalTimeHQ; //total time spent by all jobs in high priority Q
  int totalJobsHQ;    //total jobs in HQ run so far
  double avgWaitHQ;   //average wait in HQ
  double totalTimeMQ; //total time spent by all jobs in med priority Q
  int totalJobsMQ;    //total jobs in MQ run so far
  double avgWaitMQ;   //average wait in MQ
  double totalTimeLQ; //total time spent by all jobs in low priority Q
  int totalJobsLQ;    //total jobs in LQ run so far
  double avgWaitLQ;	//average wait in LQ
  double totalWorkTime; //total time spent working for all threads
  double totalIdleTime; //total time spent idle for all threads
  int workerThreads; //number of current workerThreads
  int idleThreads;   //number of current idle threads
  int persistentThreads; //number of persistent threads
  int totalThreads; //total number of current threads
  int maxThreads; //max threads so far
  int currentJobsHQ; // current jobs in Q
  int currentJobsLQ; //current jobs in Q
  int currentJobsMQ; //current jobs in Q
}ThreadPoolStats;

)


/****************************************************************************
 * Name: ThreadPool
 *
 *  Description:
 *     A thread pool similar to the thread pool in the UPnP SDK.
 *     Allows jobs to be scheduled for running by threads in a 
 *     thread pool. The thread pool is initialized with a 
 *     minimum and maximum thread number as well as a 
 *	   max idle time
 *     and a jobs per thread ratio. If a worker thread waits the whole
 *     max idle time without receiving a job and the thread pool
 *     currently has more threads running than the minimum
 *     then the worker thread will exit. If when 
 *     scheduling a job the current job to thread ratio
 *     becomes greater than the set ratio and the thread pool currently has
 *     less than the maximum threads then a new thread will
 *     be created.
 *
 *****************************************************************************/

typedef struct THREADPOOL
{
  ithread_mutex_t mutex; //mutex to protect job qs
  ithread_cond_t condition; //condition variable to signal Q
  ithread_cond_t start_and_shutdown; //condition variable for start 
                                     //and stop     
  int lastJobId; //ids for jobs 
  int shutdown;   //whether or not we are shutting down
  int totalThreads;       //total number of threads	
  int busyThreads;        // number of threads that are currently executing jobs
  int persistentThreads; //number of persistent threads
  FreeList jobFreeList; //free list of jobs
  LinkedList lowJobQ;    //low priority job Q
  LinkedList medJobQ;    //med priority job Q
  LinkedList highJobQ;   //high priority job Q
  ThreadPoolJob *persistentJob; //persistent job
 
  ThreadPoolAttr attr; //thread pool attributes
 
  free_thread_func free_func; // user defined thread cleanup function

  //statistics 
  STATSONLY(ThreadPoolStats stats;)
 
} ThreadPool;



/****************************************************************************
 * Function: ThreadPoolInit
 *
 *  Description:
 *      Initializes and starts ThreadPool. Must be called first.
 *      And only once for ThreadPool.
 *  Parameters:
 *      tp  - must be valid, non null, pointer to ThreadPool.
 *      attr - can be null
 *
 *       if not null then attr contains the following fields:
 *
 *      minWorkerThreads - minimum number of worker threads
 *                                 thread pool will never have less than this
 *                                  number of threads.
 *      maxWorkerThreads - maximum number of worker threads
 *                         thread pool will never have more than this
 *                         number of threads.
 *      maxIdleTime      - maximum time that a worker thread will spend
 *                         idle. If a worker is idle longer than this
 *                         time and there are more than the min
 *                         number of workers running, than the
 *                         worker thread exits.
 *      jobsPerThread    - ratio of jobs to thread to try and maintain
 *                         if a job is scheduled and the number of jobs per
 *                         thread is greater than this number,and  
 *                         if less than the maximum number of
 *                         workers are running then a new thread is 
 *                         started to help out with efficiency.
 *      schedPolicy      - scheduling policy to try and set (OS dependent)
 *  Returns:
 *      0 on success, nonzero on failure.
 *      EAGAIN if not enough system resources to create minimum threads.
 *      INVALID_POLICY if schedPolicy can't be set
 *      EMAXTHREADS if minimum threads is greater than maximum threads
 *****************************************************************************/
int ThreadPoolInit(ThreadPool *tp,
  ThreadPoolAttr *attr);

/****************************************************************************
 * Function: ThreadPoolAddPersistent
 *
 *  Description:
 *      Adds a persistent job to the thread pool.
 *      Job will be run as soon as possible.
 *      Call will block until job is scheduled.
 *  Parameters:
 *      tp - valid thread pool pointer
 *      ThreadPoolJob - valid thread pool job with the following fields:
 *
 *        func - ThreadFunction to run
 *        arg - argument to function.
 *        priority - priority of job.
 * 
 *  Returns:
 *      0 on success, nonzero on failure
 *      EOUTOFMEM not enough memory to add job.
 *      EMAXTHREADS not enough threads to add persistent job.
 *****************************************************************************/
int ThreadPoolAddPersistent (ThreadPool*tp,
  ThreadPoolJob *job,
  int *jobId);

/****************************************************************************
 * Function: ThreadPoolGetAttr
 *
 *  Description:
 *      Gets the current set of attributes
 *      associated with the thread pool.
 *  Parameters:
 *      tp - valid thread pool pointer
 *      out - non null pointer to store attributes
 *  Returns:
 *      0 on success, nonzero on failure
 *      Always returns 0.
 *****************************************************************************/
int ThreadPoolGetAttr(ThreadPool *tp,
  ThreadPoolAttr *out);
/****************************************************************************
 * Function: ThreadPoolSetAttr
 *
 *  Description:
 *      Sets the attributes for the thread pool.
 *      Only affects future calculations. 
 *  Parameters:
 *      tp - valid thread pool pointer
 *      attr - pointer to attributes, null sets attributes to default.
 *  Returns:
 *      0 on success, nonzero on failure
 *      Returns INVALID_POLICY if policy can not be set.
 *****************************************************************************/
int ThreadPoolSetAttr(ThreadPool *tp,
  ThreadPoolAttr *attr);

/****************************************************************************
 * Function: ThreadPoolAdd
 *
 *  Description:
 *      Adds a job to the thread pool.
 *      Job will be run as soon as possible.
 *  Parameters:
 *      tp - valid thread pool pointer
 *      func - ThreadFunction to run
 *      arg - argument to function.
 *      priority - priority of job.
 *      poolid - id of job
 *      free_function - function to use when freeing argument 
 *  Returns:
 *      0 on success, nonzero on failure
 *      EOUTOFMEM if not enough memory to add job.
 *****************************************************************************/
int ThreadPoolAdd (ThreadPool*tp,
  ThreadPoolJob *job,
  int *jobId);

/****************************************************************************
 * Function: ThreadPoolRemove
 *
 *  Description:
 *      Removes a job from the thread pool.
 *      Can only remove jobs which are not
 *      currently running.
 *  Parameters:
 *      tp - valid thread pool pointer
 *      jobid - id of job
 *      out - space for removed job.
 *  Returns:
 *      0 on success, nonzero on failure.
 *      INVALID_JOB_ID if job not found. 
 *****************************************************************************/
int ThreadPoolRemove(ThreadPool *tp,
  int jobId, ThreadPoolJob *out);



/****************************************************************************
 * Function: ThreadPoolShutdown
 *
 *  Description:
 *      Shuts the thread pool down.
 *      Waits for all threads to finish. 
 *      May block indefinitely if jobs do not
 *      exit.
 *  Parameters:
 *      tp - must be valid tp     
 *  Returns:
 *      0 on success, nonzero on failure
 *      Always returns 0.
 *****************************************************************************/
int ThreadPoolShutdown(ThreadPool *tp);


/****************************************************************************
 * Function: TPJobInit
 *
 *  Description:
 *      Initializes thread pool job.
 *      Sets the priority to default defined in ThreadPool.h.
 *      Sets the free_routine to default defined in ThreadPool.h
 *  Parameters:
 *      ThreadPoolJob *job - must be valid thread pool attributes.    
 *      start_routine func - function to run, must be valid
 *      void * arg - argument to pass to function.
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPJobInit(ThreadPoolJob *job, start_routine func, void *arg);

/****************************************************************************
 * Function: TPJobSetPriority
 *
 *  Description:
 *      Sets the max threads for the thread pool attributes.
 *  Parameters:
 *      attr - must be valid thread pool attributes. 
 *      maxThreads - value to set
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPJobSetPriority(ThreadPoolJob *job, ThreadPriority priority);

/****************************************************************************
 * Function: TPJobSetFreeFunction
 *
 *  Description:
 *      Sets the max threads for the thread pool attributes.
 *  Parameters:
 *      attr - must be valid thread pool attributes. 
 *      maxThreads - value to set
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPJobSetFreeFunction(ThreadPoolJob *job, free_routine func);

/****************************************************************************
 * Function: TPAttrInit
 *
 *  Description:
 *      Initializes thread pool attributes.
 *      Sets values to defaults defined in ThreadPool.h.
 *  Parameters:
 *      attr - must be valid thread pool attributes.    
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrInit(ThreadPoolAttr *attr);

/****************************************************************************
 * Function: TPAttrSetMaxThreads
 *
 *  Description:
 *      Sets the max threads for the thread pool attributes.
 *  Parameters:
 *      attr - must be valid thread pool attributes. 
 *      maxThreads - value to set
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrSetMaxThreads(ThreadPoolAttr *attr, int maxThreads);

/****************************************************************************
 * Function: TPAttrSetMinThreads
 *
 *  Description:
 *      Sets the min threads for the thread pool attributes.
 *  Parameters:
 *      attr - must be valid thread pool attributes. 
 *      minThreads - value to set
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrSetMinThreads(ThreadPoolAttr *attr, int minThreads);

/****************************************************************************
 * Function: TPAttrSetIdleTime
 *
 *  Description:
 *      Sets the idle time for the thread pool attributes.
 *  Parameters:
 *      attr - must be valid thread pool attributes.    
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrSetIdleTime(ThreadPoolAttr *attr, int idleTime);

/****************************************************************************
 * Function: TPAttrSetJobsPerThread
 *
 *  Description:
 *      Sets the jobs per thread ratio
 *  Parameters:
 *      attr - must be valid thread pool attributes.
 *      jobsPerThread - number of jobs per thread to maintain
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrSetJobsPerThread(ThreadPoolAttr *attr, int jobsPerThread);

/****************************************************************************
 * Function: TPAttrSetStarvationTime
 *
 *  Description:
 *      Sets the starvation time for the thread pool attributes.
 *  Parameters:
 *      attr - must be valid thread pool attributes.    
 *      int starvationTime - milliseconds
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrSetStarvationTime(ThreadPoolAttr *attr, int starvationTime);

/****************************************************************************
 * Function: TPAttrSetSchedPolicy
 *
 *  Description:
 *      Sets the scheduling policy for the thread pool attributes.
 *  Parameters:
 *      attr - must be valid thread pool attributes.    
 *      PolicyType schedPolicy - must be a valid policy type.
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrSetSchedPolicy(ThreadPoolAttr *attr, PolicyType schedPolicy);


/****************************************************************************
 * Function: TPAttrSetMaxJobsTotal
 *
 *  Description:
 *      Sets the maximum number jobs that can be qeued totally.
 *  Parameters:
 *      attr - must be valid thread pool attributes.
 *      maxJobsTotal - maximum number of jobs
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrSetMaxJobsTotal(ThreadPoolAttr *attr, int maxJobsTotal);

/****************************************************************************
 * Function: ThreadPoolGetStats
 *
 *  Description:
 *      Returns various statistics about the
 *      thread pool.
 *      Only valid if STATS has been defined.
 *  Parameters:
 *      ThreadPool *tp - valid initialized threadpool    
 *      ThreadPoolStats *stats - valid stats, out parameter
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
STATSONLY( EXPORT int ThreadPoolGetStats(ThreadPool *tp, ThreadPoolStats *stats););

STATSONLY(EXPORT void ThreadPoolPrintStats(ThreadPoolStats *stats););

#ifdef __cplusplus
}
#endif

#endif //ThreadPool
